Hydraulic pressure has the benefits of performing work efficiently, lending itself to miniaturization, quiet operation, and the options of manual as well as electronic operation.
The present invention relates generally to application of hydraulic pressure for medical treatment. Therapeutic application of hydraulic pressure to the body in the form of negative (suction), positive (tension) or traction (sliding) pressure can be used to treat a wide range of conditions, including, for example, cardiovascular, respiratory, muscular, skeletal, lymphatic and skin conditions. In some embodiments, the invention can be adapted for sleep breathing therapy, and more specifically, to provide apparatuses and methods for treating sleep disordered breathing, such as snoring, and obstructive sleep apnea, with hydraulic suction or traction used to open the upper airway.
The present invention also describes a novel traction method for externally opening the upper airway by manipulating the anatomic relationships between the skin and soft tissues of the neck and upper chest, and the hyoid bone located in the throat and directly connected to the tongue.
Obstructive sleep apnea (OSA) is a common but under-diagnosed breathing disorder affecting 1 out of 5 adults in the United States. It is caused by airway collapse and blockage when the tongue falls back in the throat and the airway walls compress the upper air passage during sleep. This causes snoring and chronic sleep deprivation that manifests as daytime fatigue, reduced mental ability, driving and work related accidents, and lower overall productivity. The silent health consequences in those with moderate or severe OSA can be serious (high blood pressure, diabetes, acid reflux, blood clots) or even life threatening (miscarriage, stroke, heart attack, or sudden death from heart rhythm abnormalities). Habitual snoring occurs in 44% of men and 28% of women aged 30 to 60 in the United States, and is responsible for significant sleep disruption for bed partners of loud snorers.
The health consequences can be serious or even life threatening in those with severe OSA. Low blood and tissue oxygen levels caused by cessation of respiration trigger the release of stress hormones like cortisol and adrenaline. These chemicals cause harmful surges in blood pressure, heart rate and blood sugar. Repetitive cycles of this process may lead to a stroke, heart attack or sudden death.
Recent human clinical research has demonstrated that the critical pressure at which the upper airway collapses and limits flow to a maximal level (PCRIT) is a measure of upper airway collapsibility and depends on the stability of the walls defining the upper airway as well as the surrounding pressure. PCRIT is defined as the pressure inside the upper airway at the onset of flow limitation when the upper airway collapses. PCRIT may be expressed as: PCRIT=PIN−POUT where PIN=pressure inside the upper airway at the moment of airway collapse; and POUT=pressure outside the upper airway (atmospheric pressure).
PCRIT is a measure of the severity of upper airway obstruction during sleep, and ranges from a level significantly below atmospheric in normal individuals to levels near or above atmospheric as upper airway obstruction progresses from snoring to hypopneas (abnormally shallow breaths), and ultimately to apneas (abnormal cessation of breathing).
PIN is increased by increased soft tissue mass around the upper airway, particularly during sleep when tissue supporting mechanisms fail in some individuals. This has the effect of compressing the upper airway, and increasing the likelihood that PCRIT will be reached.
The current state of the art in treating OSA involves the life-long use of mechanical systems that pump air (sometimes enriched with oxygen) into the upper airway via a mask that fits tightly over the nose, mouth or both. This pressurized jet of Positive Airway Pressure (PAP) counteracts upper airway collapse by forcing air in to increase POUT relative to PIN thereby restoring the negative value of PCRIT.
This technology is effective, but has the disadvantages of being expensive to purchase and maintain, and many patients find it uncomfortable and impractical to use. The overall long-term compliance with PAP is low, and usually only those with the most severe symptoms continue treatment beyond one year.
OSA can be reversed by major weight loss, but this rarely happens without stomach reduction or bypass surgery that is usually reserved for the most obese patients. Consequently, OSA treatment is usually for life. Less radical surgery involves removing the sagging tissues in the nose and throat, and carving away the back of the tongue to create room for airflow. This procedure has been proven to work in only the mildest forms of OSA.
Another treatment approach has been to wear a Mandibular Advancement Device (MAD), a dental prosthesis that prevents airway collapse during sleep by pushing the lower jaw forward to increase the size of the airway. MADs are attractive since they are worn inside the mouth and are more comfortable than CPAP, but again mild cases respond best. However, MADs may be uncomfortable, cause pain, or even injure the jaw and shift teeth. They usually require custom fitting and adjustment by an experienced dentist, making them costly. They are not a viable option for those patients with multiple missing or diseased teeth.
An urgent need remains for lower cost, safe, effective, controllable and comfortable treatment modalities for snoring and obstructive sleep apnea.
It is recognized by the inventors that a wide variety of other diseases and disorders are amenable to hydraulic pressure therapy delivered so as to promote health and alleviate disease and discomfort, whether it takes the form of suction, traction or tension singly or in combination applied against one or more body parts.